第8题: [单项选择]How can we avoid a worldwide water shortage in the future A. We can invent ways of increasing rainfall. B. We can develop ways of reusing water. C. We may use less water. D. We may build fewer steel plants. 参考答案:B 答案解析:[试题分析] 细节题。
[详细解答] 录音稿:One of the first steps is to develop ways of reusing it.
第19题: [单项选择]He ______with Smith at least four times in the past three years. A. has been seen to meet B. was seen to meet C. had been seen meeting D. is seen meeting 参考答案:A 答案解析:本题测试被动语态的时态。从“in the past three years”可知,该句应用现在完成时,可排除B、C、D项。